Thanks both of you for your replies. Silly me, i was using the line with the clunk on it to fill it up with fuel.. and the line i am SUPPOSED to be using to fill it with fuel on the engine... oops, i have swapped them back over now and i just successfully ran a full tank through using the run in instructions in the manual. I am very pleased with this engine as it is extremly quiet and blows no smoke at all (is that normal?). Anyway, thanks again.